Alfalfa Production Practices
and Variety Performance
in Southern Oregon
Circular of Information 694
March 1983
Agricultural Experiment Station
Oregon State University, Corvallis
ABSTRACT
Alfalfa is an important hay crop which is grown on more than
10,000 acres in Jackson, Josephine, and Douglas counties of
southern Oregon. Its estimated crop value is more than four
million dollars per year. Many varieties of alfalfa are available for planting in the area. Sixty-eight varieties and
experimental selections have been tested in five trials seeded
since 1973 at the Southern Oregon Experiment Station at Medford.
This report discusses the methods and recommended management
practices under which the alfalfas were grown, and it presents
yield data and observations from the trials.
KEYWORDS:
AUTHOR:
alfalfa varieties, management practices
John A. Yungen, associate professor of agronomy,
Southern Oregon Experiment Station, Medford
ALFALFA PRODUCTION PRACTICES AND VARIETY PERFORMANCE IN SOUTHERN OREGON
John
A.
Yungen
INTRODUCTION
The production of alfalfa hay is an important enterprise on many southern
Oregon farms. Alfalfa is grown on more than 10,000 acres in Jackson, Josephine,
and Douglas counties with an estimated farm value of more than four million
dollars per year. Much of the hay is consumed by livestock in the area, and
some is sold to coastal area dairies.
Alfalfa is best suited to irrigated land or to deep, well-drained dryland
soils. Yields range from three to more than nine tons per acre, depending on
climatic conditions, soil type, soil moisture, fertilizer application, stand
density, variety, disease intensity, and other management considerations.
Several root diseases shorten the productive life of alfalfa stands in
southern Oregon. Bacterial wilt, Corynebacterium insidiosum, is widespread
and may begin reducing stand densities of susceptible varieties by the second
production year. Fusarium wilt, less virulent than bacterial wilt, is found
in some fields. VerticiIlium wilt. Verticillium albo-atrum, has not been
observed in the area, although it causes stand and yield reductions in some
parts of Oregon. Phytophthora root rot, Phytophthora megasperma, causes stand
thinning on some of the heavy-textured, less well-drained soils. Foliar diseases and the stem nematode, Ditylenchus dipsaci, occasionally cause stand
damage and yield reductions. Plant breeders are making rapid progress in developing varieties with greater disease resistance, and they are placing emphasis on developing alfalfas with multiple disease and insect resistance.
Selecting the variety best adapted to conditions in a particular field is
one of the most important decisions to be made in producing alfalfa hay. Many
varieties developed by private seed companies and by public agencies are available, and prospective growers benefit from test plantings made under conditions
similar to those found on their own farms.
Alfalfas usually can be classified as being short, medium, or long rotation
types with respect to stand life. Short rotation types usually are productive
only one or two years, medium rotation types may be productive three or four
years, and long rotation alfalfas should remain productive at least five years.
Several alfalfas are used as standards of comparison for evaluating new
alfalfas in the area. Lahontan, Saranac, Thor, and Vernal are long rotation
types which have been grown for many years. Talent was released from the Southern Oregon Experiment Station in 1950 and was widely grown in southern Oregon,
western Oregon, western Washington, and in Greece for about 20 years. It has
moderate resistance to the stem nematode, but is moderately susceptible to bacterial wilt. It is a medium rotation type no longer widely grown but still used
for comparison purposes.
Variety trials have been conducted at the Medford location to identify
alfalfas best adapted to the climate, soils, and farming systems of the area.
Data from five test plantings established between 1959 and 1973 were presented
in Station Circular of Information 661 published at Oregon State University in
1977. Those tests included data on 82 varieties and experimental selections.
This publication summarizes data on 68 alfalfas from five tests established
between 1973 and 1978.
Most of the alfalfas in the tests are classed as being moderately winterhardy, although a few hardy types were included. The alfalfas were evaluated
for yield, quality, and disease resistance as indicated by length of productive
stand life. Yields were expressed in tons of dry matter per acre. Alfalfa is
usually baled while it still contains from 18 to 25 percent moisture; moisture
is gradually lost until it reaches an air-dry moisture content of 10 to 12
percent, depending on the humidity of the surrounding air and the place and
method of storage. Therefore, dry matter yields are 10 to 12 percent lower
than would be expected for air-dry hay.
STAND ESTABLISHMENT
Seedbed preparation
The alfalfas were grown on a deep, well-drained. Central Point sandy loam
soil. Soil tests, before seeding, determined fertilizer and liming needs. The
soil test values were in the lower medium range for phosphorus and potassium,
while calcium and magnesium levels were adequate. During seedbed preparation,
phosphorus was applied at 35 to 44 pounds per acre (80 to 100 P2O5), potassium
was applied at 66 to 83 pounds per acre (80 to 100 K2O), and sulfur was applied
at 30 to 40 pounds per acre, usually as part of single superphosphate. The soil
pH ranged from 6.2 to 6.4, and based on the S.M.P. lime requirement test, no
1ime was applied.
Pre-plant incorporated herbicides were used with all the plantings. EPTC
(Eptam) was applied at 2.5 pounds per acre, and benefin (Balan) was applied at
1.0 pound per acre, combined as a tank mix. The herbicides were tilled into
two or three inches of surface soil immediately after they were applied. Seeding
was done the same day or within one or two days.
Seeding
Fresh commercial inoculant was applied to the seeds at planting time.
The seeds were slightly moistened with water to increase adhesion of the inoculant.
Seeds were drilled to a depth of approximately one-half inch with a Planet
Jr. planter, and a roller or cultipacker was then used to firm the seedbed to
obtain good soil-to-seed contact. The seeding rates were 10 to 12 pounds of
pure live seed per acre. Rows were spaced 12 inches apart rather than 6 inches,
since previous work indicated no difference in yield between the two spacings.
Each plot consisted of five rows that were 25 feet long. The seedings were
all made in April since spring seedings have proved more satisfactory than fall
seedings when unfavorable weather and winter-annual weeds can cause poor stands.
Irrigation
Overhead sprinklers were used in all trials. In new seedings, irrigations
were frequent, but light, with applications of about one inch of water each time.
The Central Point sandy loam soil holds approximately 1.5 inches of available
water per foot of depth. After June 1 in new seedings, greater amounts of water
were applied but at less frequent intervals. With established alfalfa, about
five inches of water was applied as soon as possible after each harvest. Between the second and third and between the third and fourth cuttings, an additional three inches of water was applied in most years.
Irrigation before the first harvest was used only in years when winter and
spring precipitation was well below normal. Precipitation at the Experiment
Station averages about 19 inches annually.
Harvesting
New seedings were cut three times in the seedling year. The pre-plant incorporated herbicide treatment generally resulted in nearly weed-free alfalfa
so high quality hay could be produced even in the seedling year. Established
alfalfas were harvested four times per year at the late bud to early bloom
stage of development. Cutting dates were about June 1, July 6, August 12, and
September 25. Fall regrowth after the fourth cutting was not harvested but was
left to build up carbohydrates in the root systems to provide food reserves for
growth the following spring.
Weed control
Herbicides were applied in October, November, or December to established
plantings. Either diuron (Karmex) at 2.4 pounds per acre or simazine (Princep)
at 1.6 pounds per acre was used. Since 1978, paraquat, a restricted use herbicide, has been used at 0.37 to 0.5 pound per acre (1.5 to 2 pints) with
the simazine as a tank mix.
As stands became older, dinoseb (Premerge 3, Sinox PE), a restricted use
herbicide, was sometimes applied at 3.0 pounds per acre (4 quarts) in late
February as a dormant spray to control annual broad!eaf weeds escaping the fall
treatment. The competitive effect which a young, vigorous stand of alfalfa has
against weeds diminishes as stands weaken and thin, making the application of a
dormant spray a desirable practice.
Maintenance ferti1izers
Maintenance fertilizers were applied in the fall or winter each year at the
following rates per acre: phosphorus, 26 to 35 pounds (60 to 80 P2O5), potassium,
50 to 66 pounds (60 to 80 K2O), and sulfur, 36 to 48 pounds. Boron was applied
at three pounds per acre when a soil test indicated its need.
Each ton of alfalfa hay removes about 11 pounds of phosphate, P2O5, 44
pounds of potash, K2O, and 5 pounds of sulfur, S, from the soil. Although portions of these nutrients are supplied by mineralization of plant foods in the
soil, it is necessary to apply adequate amounts of fertilizer to prevent the
occurrence of nutrient deficiencies. Although alfalfa contains approximately
55 pounds of nitrogen per ton of hay, nitrogen fertilizer was not applied in
the tests because the roots were well-nodulated, and the Rhizobium meliloti
bacteria in the nodules supplied enough nitrogen to meet the alfalfas' needs.
1973 seeding
Twenty-two alfalfas were seeded in a planting that included 15 new entries
and 7 that were reference varieties or ones that had performed well in previous
trials. Most were expected to have resistance to bacterial wilt root disease.
Several were included because of their reported resistance to Phytophthora root
rot.
The alfalfas were harvested four times per year for the five full production years 1974 through 1978, but no yield data were taken in 1979. Since the
stands of many entries were still satisfactory, and many were still important
commercially, yield data were taken again in 1980, the seventh production year.
Many of the alfalfas remained productive through the seven production
years. Four entries, WL 307, WL 310, WL 311, and WL 309, produced more than
40 tons of dry matter in six production years. All but three of the 22 alfalfas averaged at least six tons of dry matter per year. Table 1 presents yield
data and stand estimates for the trial. Irrigated alfalfas in southern Oregon
generally average about 40 percent of their seasonal production in the first
cutting, nearly 25 percent in each of the next cuttings, and from 10 to 12 percent in the fourth cutting.
Percentages of the original, mature stands remaining were estimated in
March 1981. Stands of Washoe and Lahontan were given the highest ratings at
32 and 29 percents, respectively, followed closely by AS 49 and DK 167. It
was noted in this planting and in several previous ones that stands can thin
to as few as 5 to 7 plants per square foot before there are serious declines
in yields. With a seeding rate of 10 to 12 pounds per acre, the equivalent
of 50 to 60 seeds is dropped per square foot of area, resulting in more plants
than are needed for hay production. Therefore, loss of a certain number of
plants to diseases, rodents, mechanical injury, and other causes can be tolerated before the stands become too thin for satisfactory hay production.
1974 seeding
Sixteen alfalfas were seeded April 17 in a trial that included seven experimental selections along with five other new entries. Lahontan, AS-49,
Saranac, and Thor were included as standards for comparative purposes. Yield
data were taken in the seedling year and for the full production years 1975
through 1979. Table 2 presents yield data from the trial and stand ratings
from 1981 observations.
Seedling year yields, obtained in three cuttings, were high, averaging
4.36 tons of dry matter per acre. When weeds are controlled in new seedings
by the use of recommended herbicides, yields in the seedling year for irrigated
alfalfas in southern Oregon are generally about one half those obtained during
the first full production year.
Table 1.
Yields and stand ratings of alfalfa varieties and experimental selections
seeded in 1973 at the Southern Oregon Experiment Station, Medford
**'Percent
Entry
1974
Yield, tons dry matter per acre
1975
1976
1977
1978 *1980
Total
WL 307
WL 310
WL 311
WL 309
Vista
Saranac
Thor
Citation
Washoe
DK 131
Gladiator
DK 167
Vernal
Bonus
Resistador II
Talent
N7-5
AS 49
Nugget
Lahontan
Kl-610
Spredor
7.44
7.19
7.66
7.34
7.40
7.32
7.87
7.67
7.48
7.19
7.38
6.76
6.88
6.77
7.21
7.36
7.03
7.04
7.07
6.81
6.34
5.66
7.94
8.08
7.82
7.81
7.77
7.50
7.56
7.30
7.46
7.33
7.30
7.81
6.80
7.04
7.55
7.89
6.92
6.95
6.88
6.95
7.56
5.42
6.20
5.70
5.88
5.92
5.77
5.82
5.51
5.71
5.69
5.62
5.64
5.46
5.41
5.73
5.55
5.41
5.47
5.36
5.14
5.12
5.23
4.29
6.62
6.90
6.68
6.60
6.51
6.48
6.61
6.45
6.58
6.30
6.30
6.24
6.75
6.59
6.14
5,90
6.26
5.96
6.30
5.81
5.75
5.16
6.89
6.19
6.05
6.31
6.27
6.34
5.93
6.34
5.99
6.00
5.95
6.23
5.86
5.93
5.70
5.47
5.75
5.78
5.76
5.53
5.50
4.81
6.51
6.39
6.26
6.29
6.26
6.34
6.16
5.97
6.21
6.26
6.10
6.14
6.59
6.05
5.91
5.74
5.94
5.98
5.75
5.62
5.30
4.65
41.60
40.45
40.35
40.27
39.98
39.80
39.64
39.44
39.41
38.70
38.67
38.64
38.29
38.11
38.06
37.77
37.37
37.07
36.90
35.84
35.68
29.99
6.93
6.74
6.72
6.71
6.66
6.63
6.61
6.57
6.57
6.45
6.44
6.44
6.38
6.35
6.34
6.29
6.23
6.18
6.15
5.97
5.95
5.00
22
25
22
22
21
19
16
17
32
19
20
27
21
17
24
10
12
27
19
29
10
10
Mean
LSD, 5%
C.V. % .
7.14
0.49
4.9
7.35
0.60
5.7
5.54
0.38
4.8
6.31
0.52
5.9
5.94
0.58
6.9
6.02
0.52
6.1
38.29
1.74
3.2
6.38
0.29
3.2
20
Average
stand
Footnotes:
1.
2.
3.
4.
Yield data are totals of four cuttings per year.
*No yield data were taken in 1979.
**Percent stand is an estimate of the percentage of the original, mature
plants remaining as observed February 20, 1981.
Data are means of four replications.
Production levels were relatively high during the five full production years
Differences among the entries increased in the fourth and fifth years as stands
of some varieties thinned. Yields in the fifth year correlated quite well with
stands. Lahontan, Eureka, DK 167, T3X-301, AS-49, and T3X-328 were among the
highest yielding alfalfas in 1979, and they had the most plants remaining in
their stands.
Observations on March 26, 1981, when the alfalfas were seven years old,
showed that many stands had thinned beyond the point for adequate hay production.
Lahontan, Eureka, and T3X-301 had the fullest stands even though their ratings
were only 28, 27, and 27 percents, respectively, of their original full stands.
AS 49, DK 167, and experimental T3X-328 were the only others with a rating of
20 percent or more for their stands. With stand ratings below 20 percent, hay
production would be less than economic, and weed control would be more difficult than with vigorous, weed-competitive stands.
Table 2.
Yields and stand ratings of alfalfa varieties and experimental
selections seeded in 1974 at the Southern Oregon Experimental Station,
Medford
*Percent
field, 1:ons drji matter per acre
1976
1977
1978
1979 1975-79 Total Average stand
Entry
1974
1975
T3X-301
T2X-324
Thor
DK 167
T3X-303
T3X-326
T3X-328
Saranac
Americana
Klondi ke
Eureka
T3X-304
Lahontan
AS 49
Joaquin 11
T3X-308
4.49
4.73
4.33
4,27
4.69
4.42
4.76
4.40
4.74
4.43
3.94
4.36
3.94
4.15
4.01
4.28
7.75
8.38
7.88
7.65
7.82
7.98
8.05
7.85
7.81
7.66
7.41
8.12
6.97
7.08
7.01
7.65
7.35
6.83
6.93
6.70
7.20
6.66
6.61
6.97
6.86
6.48
6.30
6.72
6.46
6.23
6.15
6.77
6.24
6.32
6.17
5.90
6.23
6.03
5.76
6.00
5.97
5.83
5.66
5.69
5.70
5.35
5.63
5.40
6.71
6.48
6.67
6.22
6.02
6.36
6.14
6.06
6.22
6.30
5.97
5.44
5.90
6.06
5.79
5.33
6.47
5.71
5.98
6.82
5.87
6.07
6.43
5.95
6.00
6.12
6.60
5.71
6.64
6.52
6.24
5.24
34.52
33.72
33.63
33.29
33.14
33.10
32.99
32.83
32.56
32.39
31.94
31.68
31.67
31.24
30.82
30.39
6.90
6.74
6.73
6.66
6.63
6.62
6.60
6.57
6.51
6.48
6.39
6.34
6.33
6.25
6.16
6.08
Mean
LSD, 5%
C.V. %
4..36
0..34
5..4
7..69
6..70
0..49
5..2
5..85
0..39
4..5
6 .11
N..S.
9..3
6..15
0..70
8..0
32..50
2..15
4..6
6..50
0..43
4..6
0,.63
5,.7
27
6
19
21
12
11
20
19
11
13
27
8
28
21
18
7
Footnotes:
Yield data are totals of four cuttings per year except that only three were
made in 1974.
*Percent stand is an estimate of the percentage of the original, mature plants
remaining as observed March 26, 1981.
Data are means of four replications.
1976 seeding
Thirty alfalfas were seeded April 8, 1976, in an experiment designed to'
provide information on yield and quality of hay, adaptability, and stand persistence as influenced by root and foliar diseases. Twenty-five entries were
new to the area and five were standard reference varieties or ones that had
shown unusual promise in a previous trial. Yield data, obtained from 1977
through the 1981 season, are presented in Table 3.
Production levels remained quite uniform over the five production years.
Sixteen alfalfas exceeded six tons of dry matter production in 1981. Cumulative five-year totals ranged from 29.82 to 33.23 tons per acre, a relatively
narrow spread for 30 entries over such an extended period. Stands remained
satisfactory and still showed good vigor at the end of the test period. The
data indicates there are a number of alfalfas that remain productive over at
least five years in southern Oregon.
Table 3.
Yields of alfalfa varieties and experimental selections seeded in
1976 at the Southern Oregon Experiment Station, Medford
Entry
T3X-470
PX 755
PX 745
WL 219
Phytor
Klondike PH
*Voris A-77
Valor
Thor NL
T3X-329
Apollo
WL 215
Americana 7519
T3X-327
WL 318
Vernal
Atlas
Americana 7520
WL 216
Thor
Olympic
Pacer
Victor
K3-155
Talent
Lahontan
Anchor
T3X-469
K4-120
Discovery
Mean
LSD, 5%
C.V., %
1977
Yield, tons dry matter per acre
1979
1981
1978
1980
Total
5.47
6.17
5.68
6.61
5.88
6.62
6.46
6.12
6.21
6.20
6.01
6.29
6.54
6.59
6.35
5.64
6.31
5.95
5.94
5.91
5.92
5.94
5.74
5.82
5.59
5.33
5.85
5.92
6.36
6.08
7.68
7.60
7.54
7.50
7.55
7.59
7.42
7.37
7.60
7.02
7.47
7.60
7.25
6.93
7.34
7.24
7.31
7.28
7.31
7.41
7.32
7.08
7.16
7.52
6.59
6.70
7.03
7.13
7.37
7.08
6.89
6.49
6.75
6.28
6.37
6.16
6.29
6.09
6.10
6.65
6.09
6.22
6.00
6.35
6.12
6.33
5.81
6.03
6.10
6.06
6.00
5.82
6.05
6.08
6.19
6.32
6.13
5.99
5.64
5.60
6.44
6.41
6.11
6.01
6.24
6.08
5.94
6.21
6.07
5.90
5.93
5.79
5.95
5.90
5.81
5.96
5.88
5.95
5.73
5.66
5.69
5.80
5.89
5.56
5.87
5.85
5.61
5.53
5.22
5.52
6.75
6.40
6.92
6.42
6.46
6.05
6.13
6.32
6.13
6.12
6.27
5.77
5.79
5.62
5.76
6.09
5.95
5.92
6.01
5.97
5.79
6.06
5.84
5.66
6.02
6.05
5.48
5.34
5.28
5.54
33.23
33.07
33.00
32.82
32.50
32.50
32.24
32.11
32.11
31.89
31.77
31.67
31.53
31.39
31.38
31.26
31.26
31.13
31.09
31.01
30.72
30.70
30.68
30.64
30.26
30.25
30.10
29.91
29.87
29.82
6.65
6.61
6.60
6.56
6.50
6.50
6.45
6.42
6.42
6.38
6.35
6,33
6.31
6.28
6.28
6.25
6.25
6.23
6.22
6.20
6.15
6.14
6.14
6.13
6.05
6.05
6.02
5.98
5.97
5.96
6.08
0.61
7.1
7.29
N.S.
7.2
6.17
N.S.
9.4
5.88
0.47
5.7
6.00
0.59
6.9
31.42
1.52
4.5
6.28
0.30
4.5
Average
Footnotes:
1.
2.
3.
Yield data are totals of four cuttings per year.
Data are means of four replications.
*North American Plant Breeders is the developer and Voris Seeds is the
marketer of Voris A-77.
7 978 seeding
Twenty-four alfalfas were seeded April 25, 1978. Most were new entries,
although Lahontan, Vernal, Talent, and Thor were included as reference varieties. Several entries were selected, among many that were available, because
of their reported resistance to Phytophthora root rot, while all but Talent
were expected to be quite resistant to bacterial wilt. Yield data were taken
in the seedling year and from full-production years 1979 through 1982.
Table 4.
Yields of alfalfa varieties and experimental selections seeded in
1978 at the Southern Oregon Experiment Station, Medford
Entry
1978
Yield, tons of dry matter per acre
1979
1981
1982
1980
1978-82 Total
D3X-302
WL 310
D2X-324
D3X-353
D3X-206
WL 312
WL 219
PLC 77-133
D3X-313
Thor
WL 318
Lahontan
Resistador II
Phytor
Talent
Vanguard
Apollo
Olympic
WL 220
AS 49
NAPB 62
Vernal
Anchor
Agate
3.73
3.80
3.82
3.69
3.59
3.40
3.38
3.46
3.71
3.79
3.76
3.39
3.22
3.36
3.20
3.36
3.51
3.60
3.44
3.24
3.34
3.43
3.32
3.18
7.56
7.58
7.45
7.49
7.25
7.58
7.66
6.82
7.27
7.38
7.18
6.98
6.73
7.01
6.95
7.07
7.15
6.93
7.11
6.96
6.83
6.90
6.98
6.66
7.29
7.26
7.57
7.25
7.29
7.32
7.02
6.93
7.31
7.02
6.86
6.80
6.94
6.98
7.07
6.89
6.77
6.94
6.64
6.52
6.80
6.56
6.69
6.16
7.23
6.79
7.05
6.92
7.10
6.76
6.66
6.90
6.78
6.57
6.57
6.62
6.84
6.72
6.48
6.79
6.52
6.59
6.37
6.52
6.43
6.40
6.52
5.98
6.43
6.48
5.58
5.98
6.08
6.18
6.25
6.75
5.76
5.95
6.14
6S67
6.69
6.29
6.54
5.95
6.06
5.94
6.16
6.46
5.97
5.70
5.47
5.22
Mean
LSD, 5%
C.V., %
3.49
0.37
7.6
7.15
0.39
3.9
6.94
0.53
5.4
6.68
N.S.
6.5
6.11
0.70
8.1
'
32.24
31.91
31.47
31.33
31.31
31.24
30.97
30.86
30.83
30.71
30.51
30.46
30.42
30.36
30.24
30.06
30.01
30.00
29.72
29.70
29.37
28.99
28.98
27.20
30.37
1.79
4.2
.
Average
6.45
6.38
6.29
6.27
6.26
6.25
6.19
6.17
6.16
6.14
6.10
6.09
6.08
6.07
6.05
6.01
6.00
6.00
5.94
5.94
5.87
5.80
5.80
5.44
6.07
0.36
4.2
Footnotes:
1.
2.
Yield data are totals of four cuttings per year except that only three
cuttings were made in 1978, the seedling year.
Data are means of four replications.
Seedling year yields ranged from 3.18 to 3.82 tons of dry matter per acre
with an average of 3.49. This was lower than is usually obtained the seedling
year, with the third harvest averaging only 0.53 tons. There was no irrigation
water applied between the second and third harvests, although 1.69 inches of
precipitation was recorded. Data are shown in Table 4.
8
The alfalfas have been vigorous growers during the course of the trial.
Fourteen yielded at a rate exceeding seven tons of dry matter per acre in 1979,
ten in 1980, three in 1981, but none in 1982. Cumulative yields range from
27.20 to 32.24 tons per acre. The trial will be continued through the 1983
season.
Northwest uniform seeding
Eleven alfalfas comprising a group of varieties to be tested at several
northwest locations were seeded April 17, 1974. The objective of the trial
was to make varietal comparisons with respect to root and foliar diseases,
insect damage, hardiness, and yield of hay at several locations under widely
differing soil and climatic conditions. Yield data were taken from three
harvests in 1974 and from four harvests in each of the six succeeding years.
Data are shown in Table 5.
Table 5.
Yields and stand ratings of alfalfa varieties seeded in 1974 at the
Southern Oregon Experiment Station, Medford, Northwest Uniform Group
Entry
1974
Yield, tons dry matter per acre
1975 1976 1977 1978 1979 1980
1975-80 T/A
Total Average
Vernal
Saranac
Beltsville 72
Narragansett
Agate
Washoe
Team
Lahontan
Moapa 69
Apalachee
DuPuits
4.01
4..02
4.20
3.76
3.72
3.43
4.04
3.40
3.48
4.14
4.26
7.00
7.60
7.65
7.02
7.37
6.99
7.67
6.66
7.24
8.02
7.76
6.26
6.54
6.69
6.07
5.95
5.69
6.55
5.69
5.88
6.52
6.35
6.30
6.12
6.48
6.42
6.25
5.65
6.04
5.35
5.60
5.27
5.70
6.68
6.26
5.98
6.04
6.10
5.85
5.66
5.47
5.21
4.93
4.79
7.09
6.43
6.19
6.92
6.70
6.96
5.32
6.49
5.57
4.51
4.07
6.34
5.98
5.74
6.13
6.14
5.98
5.03
5.86
5.20
4.61
3.87
39.67
38.93
38.73
38.60
38.51
37.12
36.27
35.52
34.70
33.86
32.54
6.61
6.49
6.46
6.43
6.42
6.19
6.05
5.92
5.78
5.64
5.42
Mean
LSD, 5%
C.V., %
3.85
0.33
8.1
7.36
0.49
6.5
6.20
0.37
4.7
5.93
0.51
6.8
5.73
0.50
6.8
6.02
0.51
6.7
5.53
0.49
7.0
36.77
1.88
3.8
6.13
0.31
3.8
Percent
stand
20
21
20
21
23
31
7
28
8
3
2
Footnotes:
Yield data are tgtajs of four cuttings per year except that only three cuttings were made in 1974, the seedling year.
Percent stand is the percentage of the original mature stand remaining as
observed February 20, 1981.
Data are means of five replications.
Yields of Apalachee and DuPuits were high compared to the other varieties
from 1974 through 1976. Their stands began thinning rapidly by 1977 because of
bacterial wilt, and yields declined sharply. The material harvested from plots
of those two alfalfas in the last three harvest years contained a considerable
amount of weedy material. By February 1981, they had only a few scattered alfal
fa plants remaining.
9
The stand of Team alfalfa thinned rapidly after the 1977 season, and its
yield declined in the following three seasons. The stand of Beltsville 72
showed some thinning, but its yield remained relatively high.
Moapa 69, the only non-hardy alfalfa in the trial, was the first to begin
spring growth, was the quickest to recover after each cutting, made the most
fall growth, but was always below average in yield. It lost some plants because
of winterkill, and had only a few plants remaining in 1981.
Lahontan and Washoe yielded above the trial means beginning in 1979 and
1978, respectively. Both are characteristically in the lower half of the yield
scale in most trials in southern Oregon for the first three or four years, but
progress up the scale by the fourth or fifth years because of excellent stand
persistence. They had the highest stand ratings in the 1981 observations.
They combine high degrees of bacterial wilt resistance with resistance to Phytophthora root rot and the stem nematode.
Agate yielded well each year. It has the most Phytophthora root rot resistance of the alfalfas in the trial, and it is commonly seeded on some of the
heavier-textured, less well-drained soils in the area, Narragansett was also
very productive and maintained a reasonably good stand. Saranac performed
well, yielding above the yearly mean throughout the test. It has been a recommended variety in the area for nearly ten years.
Vernal had the highest cumulative yield of the alfalfas in the Northwest
Uniform Group. It maintained a high level of production throughout the test,
although it showed considerable stand loss as observed in 1981. Vernal is
widely grown in southern Oregon where it is often seeded on non-irrigated land.
SUMMARY
Five plantings of alfalfa made at the Southern Oregon Experiment Station
since 1973 have been used to evaluate 68 varieties and experimental selections
that might be used for hay production in Jackson, Josephine, and Douglas counties
of southern Oregon. Hay yield, along with disease resistance, as indicated by
growth, vigor, and persistence of stands, was used as the main criteria for
measuring adaptability.
Management practices recommended to growers were followed in the alfalfa
variety tests. This included inoculating the seed, firming the seedbed with a
roller or cultipacker after seeding, applying herbicides registered for the
crop, irrigating as needed, applying fertilizer according to soil test recommendations, harvesting the alfalfa at the late bud to early bloom stage of
development, and allowing fall regrowth to replenish food reserves in the root
systems. All trials were conducted on a Central Point sandy loam soil, which is
a deep, well-drained soil adapted for alfalfa production.
Found in each trial were alfalfas that had sufficient root disease resistance to maintain satisfactory stands and a high level of production over a
period of five years. Many of the alfalfas were similar in their production over
the lengths of the trials. Cumulative yields, however, over periods ranging
from four to six years, show differences within the trials. Thus, variety
10
selection continues to be important in alfalfa hay production. Although no
single variety stands out which can be recommended over all others for hay
production, these data do provide a basis on which to make variety selection
decisions for southern Oregon.
11